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MATH / How many of the natural numbers from 1 to 800, inclusive, contain the digit 6 at least twice? (The numbers 266 and 663 are two natural numbers that contain the digit 6 at least twi…

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problem

How many of the natural numbers from 11 to 800,800, inclusive, contain the digit 66 at least twice? (The numbers 266266 and 663663 are two natural numbers that contain the digit 66 at least twice, but 430430 or 1616 are not.)
Plain-text mathematical notation (without MathML)
How many of the natural numbers from 1 to 800, inclusive, contain the digit 6 at least twice? (The numbers 266 and 663 are two natural numbers that contain the digit 6 at least twice, but 430 or 16 are not.)
Original LaTeX notation
How many of the natural numbers from $1$ to $800,$ inclusive, contain the digit $6$ at least twice? (The numbers $266$ and $663$ are two natural numbers that contain the digit $6$ at least twice, but $430$ or $16$ are not.)

level

Level 4

type

Counting & Probability

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